MAINTAINERS: return arch/sh to maintained state, with new maintainers

Add Yoshinori Sato and Rich Felker as maintainers for arch/sh
(SUPERH).

Signed-off-by: Rich Felker <dalias@libc.org>
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Acked-by: D. Jeff Dionne <jeff@uClinux.org>
Acked-by: Rob Landley <rob@landley.net>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>